Take it into an alignment shop and pay the $50 to have it aligned.  I tried several times to align mine(toe) with a tape measure and still had death wobble.  Took it in and I was slightly toed out.  They also measured the caster for me.  From what I've read, you want 2-5 degrees of caster with big tires, mine was 4.5.

With big knobby tires (I run 35" MTR's) it's difficult to get a good read.  Mine drives soooo much better after the alignment.